Netflix / they took money without my permission!

I joined Netflix and signed up thinking that it was a free account, but later they took my money for some sort of membership. All I wanted was to try their service and I was never planning to buy a membership. I contacted their support and demanded my money back. They said I will be given a refund and that was the last thing I heard from them. Then I contacted my credit card company and they blocked Netflix. I don't recommend this site. They are running some kind of scam.